The Shield Mini Sight 2 (SMS2) is the a updated version of their famous original mini-sight. The first red-dot sight developed solely for pistols. Version 2 comes with an all-new design made from a stronger glass-filled nylon polymer and an improved lens with Si02 Quartz hard coating for extra resilience to the daily wear and tear of shooting. Its iconic design still allows shooters to co-witness with standard iron sights thanks to its incredibly low profile and unobtrusive design with rear iron sight notch. It carries on Shields philosophy to make its users better shooters by eliminating what is not needed and providing the shooter with just one point of focus. They dont have a large sight housing blocking vision, dimmed lenses, buttons to switch or backup sights blocking the view. Shield make their sights to fit as close to the bore-line as possible, where a trained shooter is naturally going to present their pistol allowing for a seamless transition and a familiar but improved shooting experience. Shield Sights are made by shooters for shooters. The Glass Edition has an all new scratch-resistant ultra clear Glass Lens, and upgraded electronics with improved battery contacts with the same frame and low-profile that allows you to co-witness with standard iron sights.Features :Parallax FreeOne 3V Lithium Battery, Cr2032Nylon Glass Filled PolymerCompatible With Night VisionScratch-Resistant Ultra Clear Glass Lens4Moa Dot